ref: 97d6d9ddaada7a5576ade7c6dcf4e428e236f0a0 dir: /sys/src/libc/386/387/sin.s/
TEXT sin(SB), $0 FMOVD a+0(FP), F0 FSIN RET TEXT cos(SB), $0 FMOVD a+0(FP), F0 FCOS RET